Many situations arise where so-called "grouped metering" is resorted to. In multiple tenant buildings, for example, electrical power usage by the various tenants is typically separately metered for billing purposes. This requires a separate watthour meter for each tenant. For economy of installation and convenience in reading the plural meters, they are typically grouped together in one or more enclosures or panelboards adjacent the location of electrical service entry to the building. In some installations these panelboards are located outside the buildings, and thus must be weatherproof and most especially, raintight.
It has typically been the practice to design grouped metering panelboard enclosures to accommodate the plural watthour meters and associated electrical equipment as vertically arrayed meter sections. Access to these meter sections is afforded by a single full-height front cover. The cover is provided with vertically spaced openings to expose the meter socket of each meter section into which the watthour meter is plugged. Typically, the meters can be plugged in and out without having to remove the cover. This single full-height cover approach has the distinct disadvantage of exposing, upon removal of the cover, possibly live conductors in all of the meter sections, when access to only one section is desired by the electrician. The potential for personal injury under these circumstances is unnecessarily great.
To alleviate this potentially hazardous situation, grouped metering panels are being designed with plural front covers, one for each meter section. Thus, the cover to one meter section can be removed to provide access to the electrical equipment associated with that section. The other covers can remain in place to prevent inadvertent contact with live parts in the meter sections obscured thereby. The use of multiple front covers in lieu of a single full-height front cover makes weatherproofing of the panelboard enclosure more difficult. To make the enclosure raintight, the covers are typically "shingled", in that the lower edge of one cover overlaps the upper edge of the cover immediately below. Since, in existing designs, each cover is formed with a circular opening accommodating a watthour meter, removal of a cover with the meter in place requires considerable vertical separation between meter sections. This is due to the fact that the shingling precludes removal of the cover by simply pulling it forward, away from the panelboard. Sliding the cover downward to clear the overlapping edge of the cover immediately above is precluded by the interference of the upper half of the meter opening with either the meter or, depending on the design, the meter socket. Thus, successful removal of a single cover requires coordinated manipulations of swinging the bottom of the cover away from the panelboard about its upper edge while sliding the cover downwardly to clear the overlap with the cover above. With a meter in place, the radius of the arcuate movement of the lower half of the meter opening must be long so as to clear the front end of the meter. In other words, the spacing of the meter opening relative to the upper edge of the cover must be greater than is otherwise necessary if the cover is to be readily removable. As a consequence, grouped metering panelboards having multiple front covers have been considerably larger in size, particularly in height, than is necessary to accommodate the equipment for which it is designed. This limits the number of meter sections that can be stacked in a single panelboard vertical section. In larger installations, additional floor space for panelboard sections is required, something that may not be readily available. Moreover, this increased size contributes significantly to higher materials and fabricating costs.
It is accordingly an object of the present invention to provide an improved grouped metering panelboard.
An additional object is to provide a panelboard of the above character having stacked meter sections individually accessible through separate front covers.
Still another object of the invention is to provide a grouped metering panelboard of the above character which is smaller in size than prior art designs.
A further object is to provide a grouped metering panelboard of the above character which is efficient and economical in design and conveniently serviceable by electricians in relative safety.
Other objects of the invention will become apparent from the detailed description to follow.